In a variety of downhole cementing operations, a cement slurry is mixed at a well site via a cement mixing system. The cement slurry is then delivered to a pumping system which is used to pump the cement slurry downhole into a wellbore. For example, the cement slurry may be delivered to a downhole location and forced under pressure into the annular space between a well casing and a surrounding wellbore wall. Upon curing, the well casing is cemented in place within the wellbore and the space between the well casing and the surrounding wellbore wall is sealed. When the cement slurry is mixed, delivery and handling of the powder cement blend and slurry fluid prior to delivery to the pumping system can have a substantial impact on the quality and consistency of the cement slurry.